Bridgestone Outlines Steps Taken to ‘Green’ its Tyres

Bridgestone Europe’s updated environmental report is a document the company says sets out its “commitment to high environmental standards and the latest steps to achieve them.” This third edition of the ‘Environmental Commitment and Performance’ brochure continues the focus on the Life Cycle Assessment (LCA) of tyre environmental impact from cradle to grave that has been a feature of the publication since its initial launch in 2006, and this year’s report also includes additional information on Bridgestone’s ‘Ecopia’ tyre range.

The 24-page document begins with Bridgestone’s environmental mission statement: “We, the Bridgestone Group, are committed to achieving ever higher levels of society’s trust and employee pride. We consider the environment and health and safety matters to be integral and important parts of all our business activities, as we work towards a sustainable society.”

According to the latest report, Bridgestone Corporation now uses a “small proportion” of post-consumer recycled tyre material in its tyre lines, and notes that most of the zinc oxide used in tyres comes from recycled zinc. However the manufacturer comments that “using a level of recycled contents in tyres generally shows negative effects on tyre wear and rolling resistance, and thus on fuel consumption, due to a loss of chemical reaction in the material.” Furthermore, the “limited and unstable supply of high-quality crumb rubber, and recycled materials in general, restricts the recycled content in tyres.”

In terms of the resources consumed to produce its tyres, Bridgestone Europe reports that for every tonne of tyres produced in its plants, the six years between the start of 2003 and end of 2008 has seen resource usage reduce considerably: Water intake decreased 31.1 per cent to 6.2 cubic metres per tonne of tyres manufactured, the amount of solvents used more than halved to 3.0 kilogrammes per tonne of tyres, waste generated decreased 10.5 per cent to 51 kilogrammes per tonne, and the amount of energy consumed to produce a tonne of tyres reduced 10.3 per cent to 8.7 gigajoules. Since 1990, Bridgestone adds, the amount of energy consumed has declined 48.8 per cent.

As the LCA study conducted by the European Tyre and Rubber Manufacturers’ Association in 2001 shows, 84 per cent of the average passenger car tyre’s environmental impact occurs during use. Bridgestone states it is “taking important steps to minimise environmental impact in all tyre life stages” and is “currently engaged in a major development programme in the tyre usage stage.” This centres upon lowering rolling resistance while minimising the trade-off that traditionally occurs in the form of reduced grip, especially on wet surfaces. Bridgestone’s recently released NanoPro-Tech (Nanostructure-Oriented Properties Control Technology), an agent that reduces heat generation in the top tread compound, is promoted by Bridgestone as part of the solution to this compromise between rolling resistance and grip. The tyre maker has utilised its NanoPro-Tech in the Ecopia range of ‘eco-friendly’ tyres, and to demonstrate the improvements brought through its use reports that its Ecopia EP150 tyre can make a vehicle up to three per cent more fuel efficient. Bridgestone says it now intends to implement Ecopia technology in other segments, including truck and bus tyres.

Five main uses for old tyres are outlined in the latest Environmental Commitment and Performance brochure. The most common of these is material recycling; the according to ETRMA data released last November, in 2008 some 39 per cent of old tyres in Europe were converted into rubber products for consumers usage or the construction and related industries. A further 36 per cent of old tyres were used for energy recovery purposes, mainly in power plants and cement kilns. The fate awaiting another eight per cent of these tyres was direct re-use or export, and six per cent ended up in landfill – a mere fraction of the 62 per cent of tyres so treated in 1994.

The fifth use for old tyre is, of course, retreading. As any reader of T&A’s ‘Retreading Special’ will know, this is a thriving industry; ETRMA figures indicate 11 per cent of all tyres in Europe were re-used through retreading. Bridgestone states that for truck tyres this figure jumps to more than a third, and reports the environmental benefits of retreading to include an energy consumption during production just 30 per cent of that required for a new tyre and the use of only 26 litres of oil to make a retread as opposed to 83 litres for a new tyre.

A pdf version of the current Environmental Commitment and Performance brochure can be downloaded from the bridgestone.eu website. Bridgestone says it work has already begun on a new edition, which is scheduled to be released before the end of 2010.